1. Field of Invention
The present invention relates to an inspection system, and more particularly to a non-contact automated optical inspection system suitable for inspecting the runout tolerance of a circular saw blade.
2. Related Art
As the industrial products become increasingly sophisticated, higher demands are raised on the precision of the cutting tools. A circular saw blade is an essential tool for cutting materials, and is widely used in various manufacturing industries. If an amount of radial runout and an amount of axial runout of the circular saw blade are too large, uneven cutting amount and wear degree of each tooth of the circular saw blade are caused, such that the cutting quality and the durability of the circular saw blade are poor. In quality control of the products of a circular saw blade manufacturer, the radial runout tolerance and the axial runout tolerance of the finished products of the circular saw blades must be inspected to ensure that the products of the circular saw blades can achieve desirable cutting quality and durability.
The amount of radial runout is defined as a maximal relative deviation between radial positions of apexes (tips) of the teeth upon rotation of the circular saw blade; and the radial positions are positions of the apexes (tips) of the teeth measured with respect to a reference along a radial direction of the circular saw blade. The radial runout tolerance is generally specified within the range of ±0.03 mm (millimeter) to ±0.06 mm depending on the size of the circular saw blade.
The axial runout tolerance is defined as a maximal relative deviation between axial positions of boundaries of the teeth at the same side upon rotation of the circular saw blade; and the axial positions are positions of boundaries of the teeth measured with respect to a reference along an axial direction of the circular saw blade. The axial runout tolerance is generally specified within the range of ±0.03 mm to ±0.08 mm depending on the size of the circular saw blade.
In a conventional inspection method of the runout tolerance of the circular saw blade, a measuring tool such as a dial indicator is used. During the inspection process, a probe of the dial indicator contacts with the teeth along the radial direction or the axial direction, and then the circular saw blade is rotated. Then, the amount of radial runout or the amount of axial runout of the circular saw blade can be calculated through a relative variation indicated by the dial indicator, and whether the amount of radial runout or the amount of axial runout falls within a specified tolerance range can be evaluated accordingly. However, this method has low efficiency, and may cause surface wear of the probe of the dial indicator due to the contact inspection, thus resulting in the error in inspection.